In mobile communication, a “central evolved NodeB (eNB)—distributed terminals” mode is adopted. In this mode, it is difficult for a mobile terminal to implement coordinated transmission and reception. To facilitate data detection performed by a UE (User Equipment, user equipment) and improve channel capacity, in a downlink point to point system, a MIMO (Multiple Input Multiple Output, multiple input multiple output) precoding technology is generally used in an eNB. The MIMO precoding technology means that the eNB preprocesses, in a case in which CSI (Channel State Information, channel state information) is known, data to be sent.
In the prior art, in an LTE-A (Long Term Evolution-Advanced, Long Term Evolution-Advanced) system, to provide higher cell average/edge/peak spectrum efficiency, the UE needs to send a channel information matrix that approaches a channel status as closely as possible, that is, a non-constant modulus channel information matrix. After receiving the non-constant modulus channel information matrix fed back by the UE, the eNB directly conjugates the non-constant modulus channel information matrix to obtain a precoding matrix, and precodes the data to be sent according to the precoding matrix. However, this causes a loss of transmit power.